This invention relates to a spectrophotometer, and more particularly, to a spectrophotometer system having an improved filter and source changer.
In the past, spectrophotometers have typically had continuously driven filters placed end-to-end each having a length proportional to the spectral range to be utilized with the filter. Thus, a filter for a spectral range of 100 nanometers has been twice as long as a filter for a spectral range of 50 nanometers, and only one-tenth as long as a filter for a range of 1,000 nanometers. While these filters have been somewhat satisfactory, some of the filters have been cumbersome due to their great lengths, and some imprecision in data has occurred because of filter characteristic variations along the lengths of the filters. Imprecision has also occurred at data points corresponding to the boundaries of adjacent filters.